When is a chainstay too short?

[RedRider]

I like my present Ebike, it happens to have a CS of 460.
I like to climb.
I have decided my next will be shorter for that playfull feeling.
I check specs sheets, i see 430 to 470 mostly.
I know a demo is great but according to your experience does it get tougher to climb at X #?
I do not care about speed.
I do not want to be fighting non stop to keep the front down.
Happy trails.

 

[rockcrusher]

Chainstay length relates to wheelbase, seat angle, head angle, etc. However the shorter the chainstay, generall, the better it will climb up steep stuff. However it will also want to rotate more. With an ebike with your limitations being not strength but traction it might be that you want a longer chainstay to keep the wheel on the ground and reduce overturning.

Playfulness can be some many different things from fork rake and trail to chainstay length to wheelbase and BB drop. It is all super complicated.

I can say back in the day I had a really short CS bike and it climbed up steep technical stuff like a champ but it was a handful on descents and in braking zones. I had a bike with really long CS and it was great on long climbs, ok on technical descents, as long as I could keep traction but not very maneuverable in trialsy stuff, super tech ascents or descents but it straight up ripped on fast descents. Geometries are complex and if you could get a bike that had all other measurements the same and only have a change in CS length you might be able to determine if this was for you. However chances are you might buy your next bike based on CS length and find it just the same at climbing things or just as playful or not playful as your old bike because it has shorter CS but slacker seat tube angle and a longer front center. Demo ride is the best way to determine if something works for you bar none.

 

[RedRider]

Thank you so much.
Where i ride a lot no demo come so i was hoping for an answer but hopefully i will be able to use my old method. Buy used, resell if i do not like but here decent used Ebikes are very few. I have a 27.5+ so traction is not a problem. I will not go back to thin rims.

 

[rockcrusher]

If there are others that you ride with, assist or no, you should try their bikes. If you like their bike geometry it will give you at least a guideline of what to match up. I do that with commuting bikes, haven't been able to demo what I want and so have been basing my bikes of an older bike that I like and it has worked well for me. I did the same for my first 29er borrowing a buddies 29er and trying it out on a typical loop and getting a feel for what that tire size meant for me. It was good enough that I ended up buying a bike like it and riding it until I broke it.

Check out your regional forum to see if someone has something you could borrow that is similar to what you are interested in.

 

[RedRider]

I am in no rush, i am allways shopping for my next bike. I enjoyed a Norco 2 hrs demo but other things about that bike i did not like. The feel was spot on. It think CS is 445. I try to learn by riding, reading, asking. I just started doing expert trails so i feel great. Still i am no expert but progressing.

 

[jfkbike2]

How tall are you? I think for tall riders a short CS can be a real PITA. As your seat post extends upward your weight get further behind the BB. I have a Pivot Les and at 434 I can't keep the front wheel down on a steep climb. I would stay in the 450 range if you are tall. I am 6'5" but have a longer torso than legs. My seat height is at 81.5 cm from center of BB to top of saddle.

 

[vikb]

I'm 5'11" and my bikes have the following CS lengths:

- 424mm
- 427mm
- 429mm

I typically ride bikes with approximately 460mm Reach and 635mm Stack.

I love to climb the more techy the better. I have no desire for longer CS. I have no issues keeping the front end down with my current bikes. Traction is great with my weight over the rear tire. I'm not looking for even shorter CS, but I don't want longer CS either. I pretty much lose interest if a bike had CS longer than 430mm.

 

[Nurse Ben]

There is no rule of thumb for chainstay length. Some folks think they can feel a change in handling with a shorter/longer chainstay. Some folks conclude that the longer the front center, the longer the rear center. My observations are more practical:

A longer wheelbase takes more distance to make the same turn as a short wheelbase
A shorter rear center (chainstay) allows greater weight shift to the rear wheel

So a short wheelbase is typical more agile, easier to manual, easier to "slarve", better for making tight turns.

The critics of short wheelbases cite increased difficulty with keeping the front end down on climbs and instability at speed.

What is "short"? For an all mountain bike, anything under 435mm, perhaps 440mm if you really want to stretch the definition.

There are only two "short" chainstay ebikes: Pivot Shuttle (437mm), Fezzari Wire Peak (435mm).

Good luck finding either of these bikes used.

Edit: So I concur with Vik on riding non ebikes with chainstays longer than 430mm, BUT I have experienced difficulties keeping the front end down on steep climbs when riding an ebike because the initial surge of power can be difficult to manage until the biker is able to get forward enough to control the surge.

^ This is most often a problem when starting from a stop on a steep slope. To correct this issue I have changes our Shuttle to low gearing, as you would on a non ebike, so currently my wife is running an 11-46 x 30; stock was 11-42 x 34. I'd consider going down to a 26t or 28t if I could find a direct mount chainring to fit.

 

[RedRider]

I am 5 11 with seat lower than yours by 1 in so we have very different needs.

 

[RedRider]

I am in my forth season, just started playing in expert trails but i am no expert. I also love to climb do some technical and some flow. My Ebike is a very good match for my needs except that 460 CS. I am shopping for my next Ebike that will have a shorter chainstay. I have seen the Marin(Shimano) is short but i love my Yamaha.

 

[reamer41]

When the back wheel won’t fit!

 

[RedRider]

I am pretty much OK restarting.
- Day 1 i switched from 11-36 to 11-42
- with 40 mm and 2.8 i have grip. To have even more Grip my Rekon is mounted reversed to the suggested arrow on the side. For my skills level + bike is a natural for an Ebike.
- usualy i allways use the same assist level in the trails so i know what the assist will do. I manage grip by selecting the proper gear. But if i do not know the trail well i just do my best, trying to be safe to ride tomorrow. I have 20 years of winters so i can be light on the pedals when needed. When i fail i go back the next day and i learn by practicing. 1 hill won my first 9 attempts but i made it the next.

 

[RedRider]

second good thing to know...
stop adding air before the BlowUp

 

[b1rdie]

The Canyon Spectral:ON has 430mm chainstays and I like it! they help on tight turns by allowing me to lean the bike down close to the ground and pull it back with ease.
They are also better for lofting the front wheel.
When climbing, the short cockpit helps transfer the weight to the front end with ease and I would rather stand up if it gets technical and traction also demands attention anyway.
The bike even came with a special e-saddle with a pitch up on the rear , and I think it was designed to induce the rider to seat closer to the nose, but I found it. unecessary.