What is the difference between this 1700mm and the 1000mm front hose?

Identical hose specification — same BH90 construction, stiffness, stainless fittings. The only difference is length: 1000mm for front (shorter lever-to-caliper run) vs 1700mm for rear (longer routing across the full bike). Both are sold separately.

Can I use this hose on a mountain bike?

Yes — BH90 is compatible with Shimano hydraulic MTB brakes including XTR, XT and SLX. Confirm your specific brake model uses BH90 specification in the Shimano dealer manual.

Shimano

Shimano Brake Hose, SM-BH90-JK-SSR, 1700mm, Rear

Name: Shimano Brake Hose, SM-BH90-JK-SSR, 1700mm, Rear
Brand: Shimano
SKU: CMB_WOW_ISMBH90JKSSL170
Price: 2410.00 INR
Availability: InStock
Author: InstaSport Editorial

₹2410.00

Description

Specification Length: 1700 mm Connection: straight-straight Can be Shortened: yes Connection Bolt Material: stainless steel Stiffness: high (5 out of 5)